A voice communication system, in which a server (a call controller) is installed on a network and voice communication is conducted via this server, is put into practice (Non-Patent literature 1, for example). In such voice communication system, a second server (provisioning server) is installed on the network in order to configure a provisioning data (configuration data) in a communication terminal for defining an operation of a communication terminal having a shape of a transceiver. When the communication terminal is powered on, the communication terminal is connected to the network and makes an access to the network, downloads configuration data (provisioning data) from the provisioning server and stores it in a memory (provisioning processing). The communication terminals is capable of PTT communication via call controller using the data.
In the voice communication system, a plurality of the communication terminals are possessed by the users of the system (a business enterprise using a communication service, for example), but the call controller or the provisioning server is managed by an provider of the system (a provider of the communication system). Individual provisioning data is configured in each of the plurality of communication terminals. The configuration of a part of or the whole of the communication terminal may need to be changed during an operation of the voice communication system.
Conventionally, an access path to the server and authority to update the provisioning data have not been provided or given to the system user in order to maintain security of the voice communication system. That is, the system user could not update the configuration data of the user-owned communication terminal by accessing the server. Thus, the system provider has written the configuration data of all the communication terminals of the system users in the provisioning server. The writing of the configuration data in the provisioning server was also needed at a change of the operation form after the operation started in addition to start of the operation of the voice communication system.